I finished Mass Effect 3 and I LOVED it , but (Huge Spoilers)

[Zim]

... No, no, no. The indoctrination theory is awful. The reason being that it basically means the ENTIRE trilogy, you know the vast amount of money we spent on DLC and games? Yea well that doesn't actually end. It would be like watching Return of the Jedi and the movie ends before the duel between Luke and Darth Vader. You wouldn't go ''Oh well that seems fair''

There are two options
1) The ending is the worst ending ever created
or
2) The indoctrination theory is right, in which case the entire plot of the 3 games is unfinished. We paid $180 (or well over $200 if you want to play the DLC as well which fills in vital gaps) to play through over 100 hours of content only for it to not end and then be met with a message telling you to pay more if you want to see the ending.